71 Gas Cap

[Robert P.]

I tried to put a sealed gas cap on my 71(which I think it is supposed to have) It now has a vented cap. When I put the sealed cap on, the car stalls and won't run.I took the fuel vapor canister apart, the filter looks clean and everything is clear.
Canister has part no. 17056582[Rochester products] and the assembly manual lists 7028129.
Has anyone had this problem or know what I could check next. Any help would be appercated.
Bob

[Joe L.]

Re: 71 Gas Cap

Bob------

Your 1971 was originally built with a SEALED fuel filler cap. No doubt about that, at all. If using such a cap now causes a problem, then you have some other fuel system problem.

A failed pressure-vacuum valve in the tank is a possible culprit. For 1970-74, the pressure vacuum function of the cap was moved to a valve located about 8" to the left of the filler opening on the top of the tank. The only solution for a failed pressure vacuum valve is to replace the tank. Be advised, though, that I'm not saying that's what your problem is. I'm saying that's ONE possibility.

[Geoff C.]

Fuel Tank Separator Clogged???? *NM*

[Robert P.]

Re: 71 Gas Cap

Joe, thanks for the response,you don't think it could have anthing to do with the vapor canister or it not being the right one? Bob

[Joe L.]

Re: 71 Gas Cap

Bob------

I doubt that the vapor cannister, or any other part of the EEC system, has anything to do with it. Besides, the GM #17056582 cannister is a correct REPLACMENT cannister for your application. It's not the original cannister, but it is a correct replacement for it. So, there's no deficiency with respect to an incorrect part being used.